feat: production deployment - full update with providers, admin, glossaries, pricing, tests

Major changes across backend, frontend, infrastructure:
- Provider system with model selection (Google, DeepL, OpenAI, Ollama, Google Cloud)
- Admin panel: user management, pricing, settings
- Glossary system with CSV import/export
- Subscription and tier quota management
- Security hardening (rate limiting, API key auth, path traversal fixes)
- Docker compose for dev, prod, and IONOS deployment
- Alembic migrations for new tables
- Frontend: dashboard, pricing page, landing page, i18n (en/fr)
- Test suite and verification scripts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

middleware/api_key_auth.py

@@ -3,6 +3,7 @@ API Key Authentication Middleware
 
 Provides reusable dependencies for API key authentication across all endpoints.
 Story 3.4: Authentification API via X-API-Key
+Story 6.4: Bind user_id to structlog context when user is resolved (logs include user_id).
 """
 
 from typing import Optional, Any, Union
@@ -69,8 +70,11 @@ async def get_user_from_api_key(
     
     try:
         from services.auth_service import get_user_by_api_key
-        
+        from core.logging import bind_request_context
+
         user = get_user_by_api_key(x_api_key)
+        if user is not None:
+            bind_request_context(user_id=str(getattr(user, "id", user)))
         return user
         
     except ValueError as e:
@@ -125,21 +129,26 @@ async def get_authenticated_user_optional(
         try:
             user = await get_user_from_api_key(x_api_key)
             if user:
+                from core.logging import bind_request_context
+                bind_request_context(user_id=str(getattr(user, "id", user)))
                 return user
         except APIKeyError:
             # Invalid API key, fall through to JWT
             pass
-    
+
     # Fall back to JWT
     if credentials:
         try:
             from routes.auth_routes import get_current_user
-            
+
             user = await get_current_user(credentials)
+            if user:
+                from core.logging import bind_request_context
+                bind_request_context(user_id=str(getattr(user, "id", user)))
             return user
         except Exception:
             pass
-    
+
     return None
 
 
@@ -167,20 +176,25 @@ async def get_authenticated_user(
         # get_user_from_api_key will raise APIKeyError for invalid keys
         user = await get_user_from_api_key(x_api_key)
         if user:
+            from core.logging import bind_request_context
+            bind_request_context(user_id=str(getattr(user, "id", user)))
             return user
         # Should not reach here - get_user_from_api_key returns None only if no key provided
         raise APIKeyError("INVALID_API_KEY", "Clé API invalide ou non reconnue.")
-    
+
     # Fall back to JWT
     if credentials:
         try:
             from routes.auth_routes import get_current_user
-            
+
             user = await get_current_user(credentials)
+            if user:
+                from core.logging import bind_request_context
+                bind_request_context(user_id=str(getattr(user, "id", user)))
             return user
         except Exception:
             pass
-    
+
     return None
 
 
@@ -198,10 +212,12 @@ async def require_authenticated_user(
         User object (guaranteed to be authenticated)
     """
     user = await get_authenticated_user(credentials, x_api_key)
-    
+
     if not user:
         raise APIKeyError("MISSING_API_KEY", "Authentification requise. Utilisez X-API-Key ou Authorization: Bearer.")
-    
+
+    from core.logging import bind_request_context
+    bind_request_context(user_id=str(getattr(user, "id", user)))
     return user